Battery terminals for automobiles and the like are generally mounted on the top of the battery. The battery poles are embedded in the battery cover during the manufacturing process by molding the cover material around the base of the terminal. Battery acid over time seeps out of the battery through the seal between the cover and the battery terminal. As the acid accumulates on the cover between the terminals the acid creates a short across the terminals which gradually reduces the life of the battery. The seal around the terminal may also be broken if the terminal is inadvertently hit or struck during handling which also allows acid to escape.
Terminals of this type are manufactured by cold casting a lead blank having an inner cavity by a process and apparatus as shown in U.S. Pat. No. 4,776,197, entitled "Process And Apparatus For Producing An Electrical Battery Pole Or Terminal," issued on Oct. 11, 1988, to Giorgio Scott. In this process an essentially cylindrical lead blank is placed between a first and a second die. When the dies are closed the blank is forced into a cavity provided in the first or upper die. The second die includes a truncated cone which is forced into the blank forming a cavity in the terminal. A number of ribs are provided on lower end of the terminal which are embedded in the battery cover to form a seal. The terminal is removed from the die and completed by process milling off the ends of the terminal in order to finish the battery terminal.
Die cast terminals are also used on batteries both on top and on the sides of the battery. However, die cast terminals are porous and subject to expansion on heating which may blow out the terminal when the electric contacts are welded to the terminal.